An oil-fired boiler thermostat...
- Thread starter pjbw
- Start date
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My existing Cotherm BBSC0063 thermostat has a cylindrical sensor which pushes into a tube on the side of the boiler. Wires lead from the thermostat to stop/start the Riello burner. (There is also a coiled overheating sensor, 110C). I am hopeful of something a bit more sophisticated with maybe two setting dials: one for burner start, the other for burner stop.
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Thank you,
My house has two heating circuits: one for upstairs, the other for downstairs. The upstairs has its motorised valve in the return pipe to the boiler, The downstairs has its motorised valve in the feed pipe from the boiler. The hot water cylinder is connected between the two circuits. As a result the hot water cylinder is always in circuit. It has its own thermostat which regulates its priority, but NOT its temperature.
Very ingenious, if not executed very well originally.
I run the burner 24/7 so as to make sure that the burner never has to heat the boiler from cold and that I always have hot water (handicapped daughter living with us).
I will give some thought about some other way of regulating the burner on/off.
My house has two heating circuits: one for upstairs, the other for downstairs. The upstairs has its motorised valve in the return pipe to the boiler, The downstairs has its motorised valve in the feed pipe from the boiler. The hot water cylinder is connected between the two circuits. As a result the hot water cylinder is always in circuit. It has its own thermostat which regulates its priority, but NOT its temperature.
Very ingenious, if not executed very well originally.
I run the burner 24/7 so as to make sure that the burner never has to heat the boiler from cold and that I always have hot water (handicapped daughter living with us).
I will give some thought about some other way of regulating the burner on/off.
Would it be possible to alter the pipework about to have 3 valves as an S Plan+ So you can have proper control of all 3 parts of the system?
S Plan +.
I really do seem to have quite a system!
I have looked at the 3-zone S Plus. I have the 3 zones but with only 2 zone valves: one for downstairs and one for upstairs. The hot water cylinder is always in circuit. It has big enough well insulated pipes to and from the pumps to allow convection when both zone valves are shut and the pumps (in series - one slow one for upstairs, fast one for downstairs) are stopped. Instead of a zone valve for the hot water cylinder I have a self-acting thermostatically controlled valve in the return pipe from the cylinder to the boiler. This 'waits' until the return hot water pipe reaches my set point and then shuts off the flow to the cylinder. (This cannot unfortunately regulate the hot water temperature.)
This gives me full control during the winter using the time switches, zone valves and pumps and in the summer hot water 24/7 without any valve or pump or time switch action.
I really do seem to have quite a system!
I have looked at the 3-zone S Plus. I have the 3 zones but with only 2 zone valves: one for downstairs and one for upstairs. The hot water cylinder is always in circuit. It has big enough well insulated pipes to and from the pumps to allow convection when both zone valves are shut and the pumps (in series - one slow one for upstairs, fast one for downstairs) are stopped. Instead of a zone valve for the hot water cylinder I have a self-acting thermostatically controlled valve in the return pipe from the cylinder to the boiler. This 'waits' until the return hot water pipe reaches my set point and then shuts off the flow to the cylinder. (This cannot unfortunately regulate the hot water temperature.)
This gives me full control during the winter using the time switches, zone valves and pumps and in the summer hot water 24/7 without any valve or pump or time switch action.
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That is what you have already.
Stat calls for heat........ Burner starts.
Stat is satisfied............Burner stops.
The boiler stat probably has the differential you are looking for. Your problem is that you are producing too much heat for too little water. You need to control the individual areas with a positive on/off thermostat, ( the end switch in the zone valves will do this). Replace your thermostatic valve on the hot water with a thermostatically controlled zone valve. When you have no demand, you will have no burner running. Of course, this may mean that sometimes you are heating up a cold boiler. If you wish to keep a hot boiler, then you will keep short cycling.
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